Display screen or portion thereof with an animated graphical user interface



FIG. 1 is a front view of a display screen or portion thereof with an animated graphical user interface showing a first image;

FIG. 2 is a second image thereof; and,

FIG. 3 is a third image thereof.

The broken lines showing of the display screen and portions of the graphical user interface are included for illustrating portions of the article and form no part of the claimed design.

The appearance of the image transitions sequentially between the images shown in FIGS. 1-3. The process or period in which an image transitions to another forms no part of the claimed design. 

CLAIM The ornamental design for a display screen or portion thereof with an animated user interface, as shown and described. 